Permutation Group

I have problems understanding part (f) of the following worked example:

[PLAIN]http://img7.imageshack.us/img7/5557/61793282.gif [Broken]

3. The attempt at a solution

So in part (f), when calculating [tex](\sigma \tau)^{9000}[/tex], how does [tex](\sigma \tau)^{818 \times 11} (\sigma \tau)^2[/tex] reduce to [tex](\sigma \tau)^2[/tex]? What happens to the [tex](\sigma \tau)^{818 \times 11}[/tex] part?